gcc/ipa-ref.h

   1 /* IPA reference lists.
   2    Copyright (C) 2010-2014 Free Software Foundation, Inc.
   3    Contributed by Jan Hubicka
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 struct cgraph_node;
  22 class varpool_node;
  23 class symtab_node;
  24
  25
  26 /* How the reference is done.  */
  27 enum GTY(()) ipa_ref_use
  28 {
  29   IPA_REF_LOAD,
  30   IPA_REF_STORE,
  31   IPA_REF_ADDR,
  32   IPA_REF_ALIAS
  33 };
  34
  35 /* Record of reference in callgraph or varpool.  */
  36 struct GTY(()) ipa_ref
  37 {
  38 public:
  39   /* Remove reference.  */
  40   void remove_reference ();
  41
  42   /* Return true when execution of reference can lead to return from
  43      function.  */
  44   bool cannot_lead_to_return ();
  45
  46   /* Return reference list this reference is in.  */
  47   struct ipa_ref_list * referring_ref_list (void);
  48
  49   /* Return reference list this reference is in.  */
  50   struct ipa_ref_list * referred_ref_list (void);
  51
  52   symtab_node *referring;
  53   symtab_node *referred;
  54   gimple stmt;
  55   unsigned int lto_stmt_uid;
  56   unsigned int referred_index;
  57   ENUM_BITFIELD (ipa_ref_use) use:2;
  58   unsigned int speculative:1;
  59 };
  60
  61 typedef struct ipa_ref ipa_ref_t;
  62 typedef struct ipa_ref *ipa_ref_ptr;
  63
  64
  65 /* List of references.  This is stored in both callgraph and varpool nodes.  */
  66 struct GTY(()) ipa_ref_list
  67 {
  68 public:
  69   /* Return first reference in list or NULL if empty.  */
  70   struct ipa_ref *first_reference (void)
  71   {
  72     if (!vec_safe_length (references))
  73       return NULL;
  74     return &(*references)[0];
  75   }
  76
  77   /* Return first referring ref in list or NULL if empty.  */
  78   struct ipa_ref *first_referring (void)
  79   {
  80     if (!referring.length ())
  81       return NULL;
  82     return referring[0];
  83   }
  84
  85   /* Return first referring alias.  */
  86   struct ipa_ref *first_alias (void)
  87   {
  88     struct ipa_ref *r = first_referring ();
  89
  90     return r && r->use == IPA_REF_ALIAS ? r : NULL;
  91   }
  92
  93   /* Return last referring alias.  */
  94   struct ipa_ref *last_alias (void)
  95   {
  96     unsigned int i = 0;
  97
  98     for(i = 0; i < referring.length (); i++)
  99       if (referring[i]->use != IPA_REF_ALIAS)
 100         break;
 101
 102     return i == 0 ? NULL : referring[i - 1];
 103   }
 104
 105   /* Return true if the symbol has an alias.  */
 106   bool inline has_aliases_p (void)
 107   {
 108     return first_alias ();
 109   }
 110
 111   /* Clear reference list.  */
 112   void clear (void)
 113   {
 114     referring.create (0);
 115     references = NULL;
 116   }
 117
 118   /* Return number of references.  */
 119   unsigned int nreferences (void)
 120   {
 121     return vec_safe_length (references);
 122   }
 123
 124   /* Store actual references in references vector.  */
 125   vec<ipa_ref_t, va_gc> *references;
 126   /* Referring is vector of pointers to references.  It must not live in GGC space
 127      or GGC will try to mark middle of references vectors.  */
 128   vec<ipa_ref_ptr>  GTY((skip)) referring;
 129 };